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Before last night’s game, a basketball player had scored an
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08 Oct 2018, 12:39
08 Oct 2018, 12:39
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Before last night’s game, a basketball player had scored an average (arithmetic mean) of 20 points per game. She scored 25 points in last night’s game, raising her average to 21 points per game.
How many games did she play before last night’s game?
A. 3
B. 4
C. 5
D. 6
E. 7
How many games did she play before last night’s game?
A. 3
B. 4
C. 5
D. 6
E. 7
Re: Before last night’s game, a basketball player had scored an
[#permalink]
08 Oct 2018, 22:25
08 Oct 2018, 22:25
1
Let us suppose the basketball player has played x games so far. If she scored 20 points per game average then her total points till date would be 20x. If she scores 25 points in the next game and ends up with an average of 21 points, then we can formulate a eqn as follows:
\(\frac{20x + 25}{x+1} = 21\)
solve for x which will give the value for the number of games played so far. x = 4
\(\frac{20x + 25}{x+1} = 21\)
solve for x which will give the value for the number of games played so far. x = 4
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Before last night’s game, a basketball player had scored an
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08 Jul 2021, 08:35
08 Jul 2021, 08:35
2
Theory: Average = \(\frac{Sum Of All The Values}{Total Number Of Values}\)
Before last night’s game, a basketball player had scored an average (arithmetic mean) of 20 points per game
Let she played x number of games
Using, Average = \(\frac{Sum Of All The Values}{Total Number Of Values}\), we get
20 = \(\frac{Sum}{x}\)
=> Sum of points = 20*x= 20x
She scored 25 points in last night’s game, raising her average to 21 points per game
Total number of games now will become x+1 [ x she played till now and 1 she played last night ]
Sum of points = Sum till now + 25 = 20x + 25
Using, Average = \(\frac{Sum Of All The Values}{Total Number Of Values}\), we get
21 = \(\frac{20x + 25}{x+1}\)
=> 20x + 25 = 21*(x+1)
=> 20x + 25 = 21 + 21x
=> 21x - 20x = 25-21 = 4
=> x = 4
So, she played 4 games before last night’s game
So, answer will be B
Hope it helps!
To learn more about Statistics watch the following video
Before last night’s game, a basketball player had scored an average (arithmetic mean) of 20 points per game
Let she played x number of games
Using, Average = \(\frac{Sum Of All The Values}{Total Number Of Values}\), we get
20 = \(\frac{Sum}{x}\)
=> Sum of points = 20*x= 20x
She scored 25 points in last night’s game, raising her average to 21 points per game
Total number of games now will become x+1 [ x she played till now and 1 she played last night ]
Sum of points = Sum till now + 25 = 20x + 25
Using, Average = \(\frac{Sum Of All The Values}{Total Number Of Values}\), we get
21 = \(\frac{20x + 25}{x+1}\)
=> 20x + 25 = 21*(x+1)
=> 20x + 25 = 21 + 21x
=> 21x - 20x = 25-21 = 4
=> x = 4
So, she played 4 games before last night’s game
So, answer will be B
Hope it helps!
To learn more about Statistics watch the following video
